Reliable OTA (Over the Air) DTV (Digital TV) reception poses many problems even on the best day. There are a number of variables that affect reception and not all are under the control of the consumer. Problems span the range of weak signal coverage, to diverse locations of the TV transmission towers, to limitations affecting optimal location of the receiving antenna.
A little known fact that accompanied the DTV OTA transition in 2009 was that the FCC published a set of planning factors that set important assumptions on the consumers receiving capability.
However, in very few instances does the consumer's reception device(s) provide the level of performance assumed by these planning factors. Generally, these conditions will only be met with an outdoor antenna, mounted at the highest point of a single family home and by using an antenna with relatively high gain. The FCC planning factors clearly pointed to a Yagi-Uda (aka Yagi) antenna, originally developed in the 1950s and still in existence today, as the preferred method to receive digital OTA signals for the majority of US consumers.
Generally, installing an outdoor OTA antenna is not an average consumer do-it-yourself (DIY) project. Specialized tools and techniques are required that are not readily available. Achieving an end result of a reliable set of signal within margin can only be determined by specialized radio frequency (RF) test equipment and the knowledge to use them. These facts coupled with a general negative feeling that a Yagi antenna on the roof is unattractive, discourages most consumers from meeting some critical technical metrics outlined in the planning factors.
The limitations and perceptions associated with outdoor OTA antennas have led to a paradigm shift to indoor antennas. There is a wide variety of indoor antenna form factors with many attempting to emulate a dipole in one or more planes. Some are also Omni-directional or attempt or purport to be. While some consumers have success with indoor antennas, many more do not.